Manometric apparatus



May 1, 1951 H. A. LARDY 2,550,701

MANOMETRIC APPARATUS Filed Jan, 3l,vv 1949 6 Sheets-Sheet l #11u/ 93 nig-111i o INVENTOR.

lHENRY A. LARDY May l, 1951 H. A. LARDY 2,550,701

MANOMETRIC APPARATUS Filed J'an. 5l, 1949 6 Sheets-Sheet 2 INVENTOR. HENRY A. LARDY ATTORNEY May l, 19.51 H. A. LARDY 2,550,701 A MANOMETRIC APPARATUS Filed Jan. 3l, 1949 6 Sheets-Sheet 5 FIG. 4 INVENTOR.

HENRY A. LARUY ATTORNEY May l, 1951 v A, LARDY 2,550,701

MANOMETRIC APPARATUS Filed Jan. 51, 1949 4es sheets-sheet 4 ATTORNEY May 1, 1951 H. A. LARDY MANOMETRIC APPARATUS 5 Sheets-Sheet 5 Filed Jan. 3l, 1949 Axis 0F RoTArloN JNVENTOR.

HgNRY A. LARDY ArToRNEY May l, 1951 H. A. LARDY MANOMETRIC APPARATUS 6 Sheets-Sheet 6 Filed Jan. 51, 1949 R.Y mw N 9 A 3 2 L m H N E PU. H l F G 9 m G. F 2 m lPatented May 1, 1951 511.1;UNITED STATES PATrENT OFFICE "i j,v `.2,550,701

\ MANoMETRro' APPARATUS Henry A. Leray', Maanen; Wis. Application January s1, 1949, serial No. 573,819

Thisinvention relates 'to manometr-io appara- A main object of the invention Vvis-to provide'a novel and vimproved manometric instrument lior 4#measuring the lamount of oxygenor other gases [,absv'orbed or evolved by tissues, micro-organisms, 'fand-"-organcH-or inorganic f/subs'tances, which is 'useful-as ananalytical v'tool in dealing with biol chemical, physiological, andother problems, such j as the follow/ing:

l1. Measurement of vrespiratory exchange in bacteria, yeast,fcell cultures, plant and animal Y tissue, spores, :andthe like. l l

f vf2. `Measurement of 'blood ylgases, and `for in- 3vestigating the `reactions .of "haemoglobin and amer blood pigments.

t i' 3. Measurement `of '-the :reduction of methylene f'fbluef'by bacteria; the -study of tissue oxidations kby the methylene *blue `method of Thunberg.

'14. Measurement of lactic and pyruvic-a'cid 'production .by normal and 'tumor vtissues. l VA'LSi-,iidy `of metabolism in uRinger-phosphate 1rsolution, or .in those solutions which 'must be maintained under physiological uconditions yof 'gas `tension, :such as Ringer-"bicarbonatey solution, lblood serum, and other physiological fluids.

.1.1 g-Reactions in which acid vor alkali is pros :duced or consumed in bicarbonate Ior `other,solun equilibrium with CO2 gas mixtures,` by

Microanalysisfof -gases with a high'degreeof ,acy and speedof operation, .especiallywhere jthe unknown f gas v constitutes less than y3%;4 l:ofI the .sampleyany gas `may be analyzed for .which an.,

` ing :the amount of 0.0.2 evolved-or absorbet V1'0 Claims. (ci, 73--19a A .still further Vobject of the invention is to .absorbentmay be found, .the absorbent :consist- 4 in .two kcomponents which ,are ,inactive until zmixed. For example, determinations of O2 are made by the use of aoidiedpyrogallolandlKOH; :and v,CO2 is `determined vby the .use `of .KMnOe and INaI. j

f 8 'Catalytic ,hydrogenations ...and .oxidations vaccelerated ,stability .of fats; .vitamin assays; photosynthesis; glycolysis inyw'hich 1a gas is absorbed or evolved. "A furtherpobject of the invention 'is toprovide .1animprovedV manometric apparatus for micro- ";9. In general.for thestudy of' any reaction ,f

tion.

provide an improved manometric apparatus employing al plurality of ,manometers `said manom- .eters Vbeing readable -without change ofthe operators position. Y `A stilll further object ofthe invention .is to provide an improved manometric apparatus 4formicro-respiration studies which utilizes a novel :principle of manometer and liasklmotion, where-in .the manometers are easily and accurately `readable while in motion,- wherein the manometers are securely supported, and wherein the manometers are easily mounted or removed. y A Y VA still fur-ther object of the invention lis" to provideV an improved manometric apparatus of thetypeA abo-ve mentioned, wherein the speed-and `amplitude of oscillation of the manometers and 'flasks `are readily adjustable, wherein the temperature of the-bath liquid may be closely controlled, and wherein improved uniformi-ty of temperature of the bath liquid is obtained. y

A still furtherob'ject voflthe"-invent-ion is to Vprovide Van il'moroved Aapparatus for -maki-ng micro-respiration studies, said apparatus ena"- bling the amount ofgas'absorbed or evolved during an analysis to be `determined'manometrically by'very simplemanipulations and observations of the apparatus, Vthe manometers 'being oscillated lin a horizontal plane about an axis which is cenltered 'betweenthe legs o1` the manometers whereby inertia reiects arefbalanced and whereby "no `iiutuations of the liquid columns in the manom- `eters `are produced Vas a result of `the oscillations'.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein: `Fix'gurle l 'is a perspective view ofa manometric 'apparatus' for micro-respiration studies constructed in accordance with the present inven- -Figure `2-is a perspective view of thelower portion of the apparatus -of Figure 1 `with the cylin- Figure 6 is an enlarged cross-sectional detail view taken on line 6-6 of Figure 5.

Figure '7 is an enlarged cross-sectional detail view taken on line 1 1 of Figure 1, showing the paths of oscillation of the manometer lefgs and the flask associated with one of the manometer units, portions of the unit being omitted for the sake of clarity.

Figure 8 is a fragmentary extended detail perspective view of the lower portion of one of the manometric units and its supporting standard, as employed in the apparatus of Figure 1.

Figure 9 is an enlarged vertical cross-sectional detail view taken through the locking member for the rotaryv table of the apparatus of Figure 1.

Figure 9a is an enlarged fragmentary crosssectional detail view taken on line 9a-9a of Figure 9.

Figure 10 is an enlarged elevational detail view taken on line lil-I of Figure 4.

g Figure 11 is a cross-sectional detail View taken on line II-II of Figure 10.

Figure 12 is an enlarged perspective detail view 4of the manometric unit release lever employed in the structure of Figures 10 and 11 and forming part of each manometric unit of the apparatus o Figure 1.

Referring to the drawings, and more parlticularly to Figure 4, 13 designates a circular base plate formed with a plurality of inwardly and upwardly directed struts I4 which terminate in a vertical boss I located axially with respect to base plate I3. Secured axially in boss I5 is the vertical upstanding tubular shaft IS. Secured to the intermediate portion of shaft I6 is a casting I1 formed with radial brace arms I8. Secured to and supported on casting l1, and located coaxially with respect to base I3 is the cylindrical tank I9, said tank being formed with a central vertically rising sleeve portion 83 which surrounds the upper `portion of shaft I6, as shown in Figure 1.

Rotatably surrounding shaft I5 and rotatably supported on the top surface of boss I5 is a vertical sleeve member 20, said sleeve member being formed with an annular flange 2l at its lower end, and with an annular shouldered portion 22 inwardly adjacent said flange. Secured to and supported onffiange 2I is the circular table member 23. Encircling sleeve member 2Il` and supported on shouldered Vportion 22 is a combined thrust and radial bearing unit 24 of any `suitable type, such as a ball bearing unit, and surrounding the sleeve member 20 is an outer sleeve 25 formed with an annular enlarged lower portion 26 which fits over and receives the outer race of bearing unit 24. A top roller bearing unit 21 is provided between the top portions of the inner sleeve member 2|! and the outer sleeve member 25.

The annular enlarged lower portion 26 is formed with an annular flange 21', to which is secured the spider member 28. Spider member 28 has a plurality of radial arms 29 extending from its circular central portion. The outer ends of arms V29 merge with a circular outer, ring portion 30.

Table member 23 is substantially larger in diameter than spider member 28. Secured to the marginal portion of table member 23 at equally spaced distances around the table member are a plurality of vertical bearing bushings 3 I. Pivotally secured for horizontal oscillation to the top end of each bearing bushing 3| by means of a headed pin member 3l received in the bushing is an inwardly extending horizontal bar 32.'- Secured to the ring portion 3D of spider member 28 at equally spaced distances thereon are a plurality of upstanding pin members 34, equal in number to the bearing bushings 3|. Each bar 32 is formed at its end with a slot 33 which slidably receives one of the pin members 34. Each bar 32 is formed at its intermediate portion with an upstanding vertical arm 35. Each arm 35 is formed with vertically spaced outwardly directed bosses 36 and 31. Secured to each arm 35 at the bosses 36-and 31 is a vertical block member 38. As shown in Figure 8, 10 and 1l, the vertical Aside marginal portions of the block members 38 are reduced in thickness as compared with the intermediate portions of the block members to define guide flanges 39, 39. Secured to` the lower portion of each block member 38 and projecting outwardly therefrom is a pin member 49. At its upper marginal portion each block member is formed with an outwardly facing recess 4I. The recess 4I and pin member 40 are located in the central vertical transverse plane of the block member.

Slidably fitting over each block member 38 is a rigid manometer supporting sleeve 42, -as shown in Figures 8, 10 and 1l. The sleeve 42 is formed of extruded aluminum or the like and has the side marginal channel portions 43, 43' which receive -the vertical ange portions 39, 39 of the block member 38. The body portion of the sleeve 42 is formed at its lower margin with.v aslot 44 which receives the pin 4IJ of the block member 38. Said body portion is also formed with an inwardly pressed vertical bulge 45 which engages in the recess 4I of the block member and frictionally interlocks therewith, thereby rigidly securing the sleeve 42 to the supporting block 38. Referring to Figures 10, 11 and l2, it will be seen that a release lever 46 is pivotally secured at 41 to one of the rearflanges of the sleeve 42 adjacent the bulge 45. Lever 46 has an upstanding arm portion 48 formed at its top end'with spaced lugs 49 andg50. Lug 49 projects inwardly of the edge of the channel portion 43 on which the lever 46 is mounted. Lug 50 projects outwardly of said channel'portion and acts to limit counterclockwise rotationlof the lever 46, as viewed inY Figure l0, between the full line position and thedotted line position thereof, shown infthe iigure. Lever 46 has a laterally extending lower arm 5I which overlies the top surface of the block member 38. Arm.5I is inwardly offset at 52 sothat the end of the arm is received within the channel portion 43. of the sleeve 42. The lower margin of arm 5I is formed with a depending projection 53 which'engages the top surface of block member 38 when lever 4B is rotated counterclockwise from the position shown in full line view'in Figure 10. By exerting a counterclockwise torque on said lever, a reactive force is developed which pushes the sleeve 42 upwardly with respect to the block member 38 and overcomes the frictional binding force between bulge 45 and recess 4I, thereby'enabling the sleeve to be readily lifted 01T the block member. Secured in a vertical position to each sleeve 42 is a conventional manometer 54, said manometer having the usual calibrated vertical arm portions 55, 56, connected at their bottom ends by. a U-bend 51, and a stem 58 depending from said U-bend. Connected to the stem 58 is the rubber reservoir 59. Secured to the sleeve 42 over the reservoir is the U-shaped bracket 66, and threaded through the bracket is the thumbscr'ew 6I, said thumbscrew having rotatably secured to its inner end a pressure foot 62 which engages 'terinediat I'iti'n efrubbr reservir 59 allyV oiprsses Said reservoir to 'pre quid flow frein the upperportion-'to the -l Wer portion'tliereof; By looseningl seiW'-'h l uid may be Vdrained vfrom Ystein 58 to the lower -o ien oil-reservoir 59,--as lieq'uirecl to regulate tile-height ef liquid Yinthe manenieter arms 455 aneineter's corneaei earnest and es', aeshownin Figures 4,

5t aane- 81.y neon vmachetes is engaged mit portieriby a flanged stud @t whieh' basses ng' brackets-5631er@ bly through ani-aperture in the 'as'slealjedf weten-head 65 andthe inside surfa'ee of sleeve B2i, thereby exerting spring rclarnping:5p'res"- sureon the bracket t3. Toirelease'tne'manoiiieters from vthe sleeves, the respective .studs-64 are pus ed outwardly; allowing the brackets 63=t`0be di'senaged from the arms 55 and 55 and tofbe rotatedvto vertical positions, wherein they 'no longer engage the arms l5e and 5S when the out? .Wardlnifessre fon studs G4 is released.

is of eaeh inanornet'er, i e., Vthe veit1 al :symmetry extending through stern `5 saine as the vertical axis Lofthe lassocite'l 'pivot bushing 3i, whereby horizontal rotary movement of the manometer arms as a result eaehsleevellr? has Vat its topend" a vright-fa-'ngrleol inwardly directed fiiat extension 'H which underlies and Supports the branch 6l of theassociated tialliadial distances from the faxes of rotation `of theirfrespfetive- Manometer* units and` consequently have relatively' large arcuate Y `excursions As shown in Figure` -1 tubular'shfaft' t5 rrises eeyond there@ end lo'feleeve es ananas secured vtlt's'topfe' afeiaeket' ``'11)lfCn/'loletwith @uopoL fsitely fe tend-ine' arms 81%,y 85. Secured te 1B-below bra'okeft83". by asu-itable clamp-83- 'irltorf-Stillfei' u-hit Y8?? employed for agitatin the liquid inuthe tank Secured .to `sleeve ".83 4"by bracket means not .shown is a heater-device es, having -therrnostatieally- `eontrollerzl regulating ineens, which maintains'the' liquid in the bath at constant temperature. Designated atS isaeonf troldbox which -eon-tains control switches eon nested `in the circuits of the various 'electrical Veler-nentslof theapparatusiwhereby 'saidielements nianometer unit. The branch El maybe releasablyseeured to the extension 'H by means of 'spring elip'sgshownrat 12. *f-" he table member 23 is formed with bosses 13, as shown in Figure 4, and' I een is rall 'eledtrc llrlotor" T4. -Dsignated at -fi-s a speed-reducing unit'mounted on up@ standing bosses-76 formed on table member'S. The-'Shaft rof niotor lll; carries a threeesteppulley TI. i-Ifhe power input shaft ofthe speed-reducing unityl' carries Ila' pulley l, A beltflcouples pulley 1B to a'selected step of the threefstep ill'e'y N.' 'The speed-reducing unit `l5`has 'an upwardly projecting vertical power output-l shaft `is'ecoentreallywoonneveted to a crank Bil, said crank being adjustable in ler"1gt`h. 'l'ie end -cff '3B isv pivotallyvcor'nieetIe-datr 8l` to a radial arrn 82 projeeting from sleeve `25. "It will be 'seen from Figures 2 and 3 that when Inotor il# i's'efriergiz'ed, erank 8l) oseillates arm-82 and sleeve `2?) around the inner sleeve meinberfZ, causing spider'fniember 28 to be oscillatedy withresjoe'ct to table-inenber-Qe around the 'axisol'ishaft ISat a e t .nt 1-ate-`o,fo`scillatio`n andwith a 'constant 'upstandf etude ose'mauon. freetime-sia therefore mounted ;may :be.i`indivdually controlled Control box '89 -may zbemounted on 'a suitable .wall surface or table adjacent the apparatus.` "I'heytubular-ish'a'ft i6. is utilizedasJa `(conduit for the Wiringassociatedwith :motor 'Mq Designated at 901s awater liottleise'ouredfby ,la selam'p'sring 9| `'to :a )vertical -rod :92 secured to the end of arm "85. Bottle Se lis held inf inverted positionand isprovided Witfnla 'dep-endingv spout. Se whosefbettoin determinen the level of liquid in the tank i 9 andwhiohr'automatioally vfeeds .liquidto the tank.` to compensate for evaporation; ythereby maintaining. ltliebath at a desired level; i; ,l 1

-Designatedtiat 193 is a. gassng manifold secured toaverticalro'd 9.4 clamped to the fend-f-ar'in v831-. .fManifold l93 may be eonnecteclto a suitable ysource ofgasl.`su`on as 'oxygen or lthe like. --The outlets of the manifold indicated at 795,. may fbe connected `by e'Xible tubingv to the respective fmanonietei 'arms-56 -ior attimes admitting the g'asvinto the v'mieroerespratio'n flasks 69. v

Base pl'ate l1331s' integrally formed "with "an upwardly projecting ve'rtieal sleevev-inern'ber vv96 Sloeaftediibeneath' 'the ftablerneniber 523.' 'Slidably positionedf-sie'eve meinlber 96 is' -a"' vertioa'1 plunger-91, said-plunger having mounted on its totem-aait berfrieuon vhoe 19B. A 'ooiledfsp'rng 99" is pesi loned yin an 'axial bore 100 Torinedjin fthe lower end p'rtionof plunger 91, said coiled i fearing- 'fbearliag at vits; 1 lower f end on 4the 'bottom of the internal bore of sleeve member 96,'therfeby biasing plunger 91 upwardly to a position in .whieh ril-ionen 4snee 'eafegages the bottom 'sur- 'ff' e o'fftabie memberizs and looks it againstrotaf around 'shaft frs. {secured to -plu'nger 91 anu 4entraine; outward1y-jtherefrom through ajca'm not ml fformeqeinth'e van of 's1eeve member et 'having 'vertically 'oiset upper and lower fp'orti'ons andan in l d intermediate portion, asi'show'n fin Fligurea, 1s a relealsearml'llZ. When arm I U2 is ino'veddownwardly to a'depressed'position yin s lot lill, as shown in Figure 9 fpl nger "91. i's

ated dow wardiy touiseneaeeomfrienorial engagement-with ta-ble neme ber 23, allowing said table member to be rotated around shaft i6 to a desired position. An operator is therefore enabled to rotate the table member so as `to examine any one of the manometer units from a single position. With arm |02 in the upper portion of slot |0|, the table member is locked by pressure foot 98 in a fixed position.

Slidably mounted around the cylindrical tank I9 is a cylindrical cover shell |03 which has an v inwardly directed top bead cooperating V.with a bottom marginal rib |04 formed on tank I9 to Support-the shell |03 in a position covering the various components carried on table member 23 beneath the ta'nk, such as the motor 14, speedreducing unit Q15, and the like. Shell formed with hand holes |05, enabling said shell to be manually'.L elevated whenever access is desired to these components.

In operationfthe flasks 69 are charged in the usual manner with the substances producing the reaction to be studied, such as respiring animal tissue or cell-suspension, and oxygen. The arms 55 and 5B of the'manometers contain suitable liquid. Before each reading, the level of the liquid in the arm 56 is always brought to the same given point by means of the rcljeaserf-screwlgofathe el in the open arm 55 is read; The vdiferencejin manometeric associated therewithrff Th reading between arm Briand arm 56 giyf'es-,the difference of pressure between?th'interiordf :the flask of the unit and the atmosphere. From this difference 1 in pressure the amount of gas which has beenevolved or absorbed in the flask can be readily found.

Fora complete discussion of various manometric methods as applied to the measurement of cell respirationfand other processes, reference is made to Manometric Methods by Malcolm Dixon, Cambridge University Press, 1934. The present apparatus employs the well known method used extensively by O. Warburg. In the apparatus originally employed by Warburg, the manometers are shaken or rocked in a vertical plane by motor" means. Due to the oscillations in the liquid inthe manometer arms produced by Such an action;-4 it is necessary to stop the motor when readings are to be taken and to manually turn the manbmeters to vertical positions in order to avoid errors in readings due to parallax.

In the apparatus of the present invention, f

readings may be accurately taken Without stopping the oscillations of the manometric units and without in any way altering the normal shaking action of the flasks. While a specific embodiment of an apparatus for micro-re piration studies has been disclosed in the -foreg n g description, it will be understood that variousfmodifications within the spirit of the invention may occur to those skilled in the art. .Therefore it is intended that no limitations be placed on the invention except as defined by the scope of ithe appended claims.

`What is claimed is:

l. In an apparatus of the character described, a .tank 'containing liquid, -a vertical manometer adjacent said tank and having a conduit in communication therewith and rigidly connected thereto extending inwardly over the top rim of the tank and carrying a flask immersed in the liquid, said conduit communicating with said ask, and means for oscillating said manometer around its verticalaxis, whereby vsaid' flask is -oscillated around said axis;

, 2. In an apparatus of the character described, atank containing liquid. a vertical VU-shaped manometer unit Yadjacent said tank, one arm of the unit having a rigid extension communicating therewith and projecting over the top rim of the tank and carrying a flask immersed in the liquid, said extension communicating with said flask, and means for oscillating the manometer around the vertical axis of its U-shaped position, whereby said flask is oscillated around said axis.

3. In an apparatus of the character described, a tank containing liquid, means for maintaining the liquid at constant temperature, a vertical U- shaped manometer unit adjacent said tank, one arm 0f the unit havingA a rigid extension communicating therewith and vprojecting over the top rim of the tank and carrying a flask immersed in the liquid, said extension communicating with said flask, and means for oscillating the manometer at a constant rate around the vertical axis of its U-shaped portion, whereby said flask is oscillated around said axis at the same rate.

4. In an apparatus of the character described, a support, a tank mounted on said support and containing liquid, a plurality Yof vertical U-shaped manometer units disposed around said tank, one arm of each unit having a rigid extension com- ;.munlcating'the'rewith and projecting over the top Yrimofthef tank and carrying a flask immersed in the liquid, said liask communicating with said @Zitnsoniand means for simultaneously osclating theV manometer units around the vertical axes of their respective U-shaped portions, whereby 'the respective flasks are oscillated around said axes.

5. An apparatus of the vcharacter described comprising a support, a tank mounted on said support and containing liquid, means for maintaining said liquid at constant temperature, a horizontal element rotatably mounted on said support for rotation in a horizontal plane, an arm pivoted to said support for'horizontal rotation with respect thereto, means providing a slidable and pivotal connection between said arm and said element, an upstanding vertical manometer rigidly carried by said arm,jsaid manometer having a rigidly connected portion communicating therewith and extending over the top rim of the tank and carrying a flask immersed in said liquid, said ask being in colrnmunication with said portion, and means for oscillating said element around its pivotal axis, whereby the ask is oscillated. ,jf

6. In an apparatus of the character described. a support, a tank mountedon said support and containing liquid, a carrier rotatably mounted on said support for rotation-around a vertical axis, a plurality of vertical U-shaped manometer units movably mounted onsaid carrier around the tank, one arm of each unit having a rigid extension communicating therewith and projecting over the top rim of the tank and carrying a ask immersed in the liquid, said ask communicating with said extension, and means for simultaneously oscillating the manometer units around the vertical axes of their respective U- shaped portions, whereby the respective flasks are oscillated around said axes.

'7. In an apparatus of the character described, a support, a cylindrical tank mounted on said support and containing liquid, a circular carrier rotatably mounted on said support for rotation around a vertical axis, a plurality of vertical U- shaped manometer units movably mounted on said carrier around the outer periphery of the tank, one arm of each unit having av rigid extension communicating therewith and'projecting inwardly over the top rim of the tank and carrying a ask immersed in the liquid, said ask communicating with said extension, and means for simultaneously oscillating the manometer units around the vertical axes of their respective U-shaped portions, whereby the respective flasks are oscillated around said axes.

8. An apparatus of the character described, comprising a support, a cylindrical tank mounted on said support and containing liquid, a circular carrier member rotatably mounted on said support for rotation in a horizontal plane, a circular spider member also rotatably mounted on said support parallel to said carrier member, an arm pivoted to said carrier member for horizontal rotation with respect thereto, means providing a slidable and pivotal connection between said arm and said spider member, an upstanding vertical U-shaped manometer unit rigidly carried by said arm, one leg of said unit having a rigid extension communicating therewith and projecting over the top rim of the tank and carrying a flask immersed in the liquid, said iiask communicating with said extension, and means for oscillating said spider member at a constant rate around said support, whereby said iiask is oscillated at the same rate.

9. An apparatus of the character described, comprising a support, a tank mounted on said support and containing liquid, a horizontal elementrotatably mounted on said support for rotation in a horizontal plane, an arm pivoted to said support for horizontal rotation with respect thereto, means providing a slidable and pivotal connection between said arm and said element, an upstanding vertical U-shaped manometer unit rigidly carried by said arm, the vertical axis of the U-shaped portion of the unit being aligned with the pivotal connection of the arm to the support, one leg of said unit having a rigid extension communicating therewith and projecting over the top rim of the tank and carrying a flask immersed in the liquid, said ask communieating with the extension, andrmeans for oscillating said horizontal element around its pivotal axis, whereby said flask is oscillated around the vertical axis of said U-shaped portion.

l0. An apparatus of the character described comprising a support, a cylindrical tank mounted on said support and containing liquid, a circular carrier member rotatably mounted on said support for rotation in a horizontal p-lane, a circular spider member also rotatably mounted on said support parallel to said carrier member, a plurality of inwardly extending arms respectively pivoted at spaced points to the peripheral .portion of said carrier member for horizontal rotation with respect thereto, means providing a slidable and pivotal connection between the inner end of each arm and the spiderinember, `an upstanding vertical U -shaped manometer unit rigid-- ly carried by each arm, the vertical axis of the U-shaped portion of each unit being aligned with the pivotal connection of its associated arm with the carrier member, one leg of each unit having a rigid extension communicating therewith and projecting over the top rim of the tank and carrying a flask immersed in the liquid, said flask communicating with the extension, and means for oscillating said spider member with respect to said carrier member, whereby the respective flasks are oscillated around the vertical axes of the U-shaped portions of the respective manometer units.

HENRY A. L ARDY.

REFERENCES CITED UNITED STATES PATENTS Name Date Schweitzer Sept. 16, 1947 Number 

